Back to the main page

Archives Of Astronomy Blog

Subscribe To Astronomy Blog RSS Feed  RSS content feed What is RSS feed?


March 24, 2006, 0:08 AM CT

European Robotics Under The Spotlight

European Robotics Under The Spotlight
The ExoMars rover will be ESA's field biologist on Mars. Its aim is to further characterise the biological environment on Mars in preparation for robotic missions and then human exploration. This mission calls for the development of a Mars orbiter
The European Robotic Arm (ERA) will be delivered to Russia this summer in preparation for a launch to the ISS in 2007. ESA and Dutch Space have organised the European Robotics Media Day for 5 April to provide the media with the opportunity to become acquainted with ERA and the engineers behind this ambitious project.

After its launch in November 2007, the 11-metre long robotic arm will perform a variety of tasks outside the ISS. With the ability to move up to 8 tonnes of equipment, ERA will play a key role in the continued construction of the ISS and will be used to move experimental equipment to different external locations. In addition, ERA will be used to move astronauts and cosmonauts around during spacewalks and use its video cameras to carry out inspections of external space station surfaces. ERA therefore has an important role to play in the maintenance and scientific utilisation of the ISS.

These uses of ERA highlight the impact that robotics has on human spaceflight missions. Robotic equipment can be used to undertake certain work in the harsh environment of space that is not suitable or possible to be carried out by astronauts, and also assists astronauts in a range of tasks to help reduce the amount of time needed for spacewalk activities.

Along with the European Columbus laboratory and the Automated Transfer Vehicle (ATV), ERA is one of ESA's main contributions to the ISS. With its seven joints and an impressive concentration of tools and electronics, the robotic arm has the flexibility to move hand-over- hand between fixed base points around the Russian segment of the International Space Station in order to perform its tasks. This flexibility is added to by the fact that ERA can be operated from inside or outside the ISS and can be controlled either in real-time or pre-programmed.........

Posted by: Edwin      Permalink         Source


March 24, 2006, 0:04 AM CT

Cannibal Stars Like Their Food Hot

Cannibal Stars Like Their Food Hot
ESA's XMM-Newton has seen vast clouds of superheated gas, whirling around miniature stars and escaping from being devoured by the stars' enormous gravitational fields - giving a new insight into the eating habits of the galaxy's 'cannibal' stars.

The clouds of gas range in size from a few hundred thousand kilometres to a few million kilometres, ten to one hundred times larger than the Earth. They are composed of iron vapour and other chemicals at temperatures of a number of millions of degrees.

"This gas is extremely hot, much hotter than the outer atmosphere of the Sun," said Maria Díaz Trigo of ESA's European Science and Technology Research Centre (ESTEC), who led the research.

ESA's XMM-Newton x-ray observatory made the discovery when it observed six so-called 'low-mass X-ray binary' stars (LMXBs). The LMXBs are pairs of stars in which one is the tiny core of a dead star.

Measuring just 15-20 kilometres across and comparable in size to an asteroid, each dead star is a tightly packed mass of neutrons containing more than 1.4 times the mass of the Sun.

Its extreme density generates a powerful gravitational field that rips gas from its 'living' companion star. The gas spirals around the neutron star, forming a disc, before being sucked down and crushed onto its surface, a process known as 'accretion'.........

Posted by: Edwin      Permalink         Source


March 23, 2006, 11:28 PM CT

New Map Of Milky Way

New Map Of Milky Way
A team of astronomers from Boston University's Institute for Astrophysical Research has produced the clearest map to-date of the giant gas clouds in the Milky Way that serve as the birthplaces of stars. Using a powerful telescope, the astronomers tracked emissions of a rare form of carbon monoxide called 13CO to chart a portion of our home galaxy and its star-forming molecular clouds.

The scientists hope the new illustration will aid in the identification of additional clouds and study of their internal structure to better understand the origin of stars like the sun, which began its life in such a cloud about 5 billion years ago. The data and images are reported in the recent issue of the Astrophysical Journal Supplement.

The eight-year project, called the Boston University-Five College Radio Astronomy Observatory (FCRAO) Galactic Ring Survey (GRS), was led by a team of astronomers based at BU, the University of Cologne in Gera number of, and the University of Massachusetts.

To produce the detailed image, the astronomers mapped the location of 13CO in the Milky Way using a large radio telescope operated by the FCRAO of the University of Massachusetts that captures and images radio emissions at a frequency near 100,000 MHz - about 1,000 times higher than FM stations. When viewed in the emission from 13CO, the clouds are far more transparent than the more traditionally studied 12CO which allowed the team to peer more deeply into their interior.........

Posted by: Edwin      Permalink         Source


March 22, 2006, 11:08 PM CT

Tectonic 'wrinkles' In Crater De Gasparis

Tectonic 'wrinkles' In Crater De Gasparis
This image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows Crater De Gasparis on the Moon.

The AMIE camera obtained this image on 14 January 2006 from a distance of about 1090 kilometres with a ground resolution of approximately 100 metres per pixel.

Crater De Gasparis is located close to the Mare Humorum, at longitude 51.2 degree West and latitude 26.0 degree South, on the lower left quarter of the Moon's Earth-facing side. It has a diameter of about 30 kilometres and can be seen with the naked eye from Earth.

The criss-cross patterns in it are called 'rilles' (these are features where the surface has sunk down to form a trench).

These rilles coincide with deep tectonic faults that have been active over a long period of lunar geological evolution. They are the result of stresses due to all the tidal forces and volcanic expansion over the lunar mantle during the last stages of lava flooding of Oceanus Procellarum.

The fact that the rilles cross the crater means that they formed after the crater. This is a good example for how geologists can determine the relative history of the Moon's surface.

This crater is named after the Italian astronomer Annibale de Gasparis (1819-1892). De Gasparis was director of the observatory in Naples, Italy.........

Posted by: Edwin      Permalink         Source


March 21, 2006, 10:28 PM CT

Resisting Radiation

Resisting Radiation
In Star Wars and Star Trek movies, people travel between planets and galaxies with ease. But our future in space is far from assured. Issues of hyperdrive and wormholes aside, it doesn't seem possible that the human body could withstand extended exposure to the harsh radiation of outer space.

Radiation comes from many sources. Light from the sun produces a range of wavelengths from long-wave infrared to short-wavelength ultraviolet (UV). Background radiation in space is composed of high-energy X-rays, gamma rays and cosmic rays, which all can play havoc with the cells in our bodies. Since such ionizing radiation easily penetrates spacecraft walls and spacesuits, astronauts today must limit their time in space. But being in outer space for even a short time greatly increases their odds of developing cancer, cataracts, and other radiation-related health problems.

To overcome this problem, we may find some useful tips in nature. Many organisms already have devised effective strategies to protect themselves from radiation.

Lynn Rothschild of the NASA Ames Research Center says that radiation has always been a danger for life on Earth, and so life had to find ways to cope with it. This was especially important during the Earth's earliest years, when the ingredients for life were first coming together. Because our planet did not initially have much oxygen in the atmosphere, it also lacked an ozone (O3) layer to block out harmful radiation. This is one reason why many believe life originated underwater, since water can filter out the more damaging wavelengths of light.........

Posted by: Edwin      Permalink         Source


March 21, 2006, 10:21 PM CT

Martian hour-glass

Martian hour-glass
Perspective view, looking north-west, from behind the 'hourglass' crater
This video and accompanying images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show an unusual flow deposit on the floors of two adjacent impact craters in the eastern Hellas Planitia region, indicating possible glacial processes.

The stereo capability of the HRSC makes it possible to animate 3D anaglyph images, based on digital elevation models. The image data have been acquired during Mars Express orbit 451 from an altitude of 590 kilometres with an original resolution of 29 metres per pixel.

The unusual 'hourglass'-shaped structure is located in the southern-hemisphere highland terrain of Promethei Terra at the eastern rim of the Hellas Basin, at about latitude 38º South and longitude 104 degree East.

Most likely the surface morphology is formed by the 'creep' of ice and debris, similar to either terrestrial rock glacier landforms or debris covered glaciers which are commonly found in high latitudes and alpine regions.

'Talus' material (or 'scree', the broken rocks that lie on a steep mountainside or at the base of a cliff) and ice-rich debris accumulated at the base of the remnant massif and filled the upper bowl-shaped impact crater which is approximately nine kilometres wide. The debris-ice mixture then flowed through a breach in the crater rim into a 17-kilometre wide crater, 500 metres below, taking advantage of the downward slope.........

Posted by: Edwin      Permalink         Source


March 21, 2006, 10:09 PM CT

Migration Of Giant Protoplanets

Migration Of Giant Protoplanets
In an article to be published in Astronomy & Astrophysics, two British astronomers present new numerical simulations of how planetary systems form. They find that, in the early stages of planetary formation, giant protoplanets migrate inward in lockstep into the central star.

The current picture of how planetary systems form is as follows: i) dust grains coagulate to form planetesimals of up to 1 km in diameter; ii) the runaway growth of planetesimals leads to the formation of ~100 - 1000 km-sized planetary embryos; iii) these embryos grow in an "oligarchic" manner, where a few large bodies dominate the formation process, and accrete the surrounding and much smaller planetesimals. These "oligarchs" form terrestrial planets near the central star and planetary cores of ten terrestrial masses in the giant planet region beyond 3 astronomical units (AU).

However, these theories fail to describe the formation of gas giant planets in a satisfactory way. Gravitational interaction between the gaseous protoplanetary disc and the massive planetary cores causes them to move rapidly inward over about 100,000 years in what we call the "migration" of the planet in the disc. The prediction of this rapid inward migration of giant protoplanets is a major problem, since this timescale is much shorter than the time needed for gas to accrete onto the forming giant planet. Theories predict that the giant protoplanets will merge into the central star before planets have time to form. This makes it very difficult to understand how they can form at all.........

Posted by: Edwin      Permalink         Source

March 16, 2006, 7:59 PM CT

Our Moon

astropaul posted a photo:

Our Moon



Eastern Moon

jtegerdine posted a photo:

Eastern Moon

Several Prominent Craters



lunar eclipse

lohengrin posted a photo:

lunar eclipse



Permalink

Source:
  • Space.com


  • March 16, 2006, 6:14 PM CT

    Mars gullies could form without water

    If you're a scientist studying the surface of Mars, few discoveries could be more exciting than seeing recent gullies apparently formed by running water.

    And that's what scientists believed they saw in Mars Orbital Camera (MOC) images five years ago. They published a paper in Science on MOC images that show small, geologically young ravines. They concluded that the gullies are evidence that liquid water flowed on Mars' surface sometime within the last million years.

    Galaxy on fire! Spitzer reveals stellar smoke
    Where there's smoke, there's fire - even in outer space. A new infrared image from NASA's Spitzer Space Telescope shows a burning hot galaxy whose fiery stars appear to be blowing out giant billows of smoky dust.

    The galaxy, called Messier 82, or the "Cigar galaxy," was previously known to host a hotbed of young, massive stars. The new Spitzer image reveals, for the first time, the "smoke" surrounding those stellar fires.

    New satellite data on universe's first trillionth second
    Scientists peering back to the oldest light in the universe have new evidence for what happened within its first trillionth of a second, when the universe suddenly grew from submicroscopic to astronomical size in far less than a wink of the eye.

    Using new data from a NASA satellite, scientists have the best evidence yet to support this scenario, known as "inflation." The evidence, from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite, was gathered during three years of continuous observations of remnant afterglow light -- cosmic background radiation that lingers, much cooled, from the universe's energetic beginnings 13.7 billion years ago.

    Permalink

    Source:

  • Space News Blog



  • March 12, 2006, 9:59 PM CT

    First Magnified View Of Mars

    First Magnified View Of Mars This artist's rendition shows the Mars Reconnaissance Orbiter at Mars. HiRISE is the gold tube-shaped instrument on the lower left of the spacecraft. (NASA illustration)
    HiRISE researchers will power the HiRISE camera the week of March 20. It will begin taking pictures 18 hours later, and it will take pictures during two orbits. NASA Jet Propulsion Laboratory mission specialists will decide exactly which orbits will be HiRISE imaging orbits after Mars orbit insertion on March 10.

    These will be the camera's only photos for the next six months because it will be turned off while the spacecraft "aerobrakes." This involves dipping repeatedly into the upper atmosphere to scrub off speed and drop into successively more circular orbits.

    The first images will be highly experimental because the team is trying many algorithms and systems for the first time, so things could go wrong, McEwen said. "However, we are sure to learn important lessons about how to operate the spacecraft and HiRISE."

    Also, the geometries of the early orbits may be less than ideal for the HiRise camera's test-image swath. And there's a chance that atmospheric dust or ice hazes could obscure the surface because it's early fall in the southern hemisphere.

    The camera will take pictures of the middle latitudes of the southern hemisphere, a region where a number of geologically recent gullies have been seen, gullies possibly carved by water. Scientists won't know the exact area they'll photograph until the spacecraft is safely captured into orbit around Mars.........

    Posted by: Edwin      Permalink         Source


    Older Blog Entries   1   2   3   4   5   6   7   8   9   10   11   12